Rotary switch



Oct. 26, 1937.

c. B. HOWA RD ROTARY SWITCH Filed Aug. 31, 1936 INVENTOR,

ATTORNEYS.

cum-Ives a. HOWARD Patented 26, 1937 2,096,745

UNITED STATES PATENT OFFICE 2,096,745 a ROTARY SWITCH Clarence B. Howard, Oakland, Calif., assignor to E. H. Kuefler Application August 31, 1936, Serial No. 98,657 4 Claims. (Cl. 200-59) My invention relates to rotary switches, and of my invention, and particularly to Figure 3, more particularly to that type of switch wherein I provide a mounting bracket l to which is atrotation in one, direction makes contact in an tached an upper casing disc 2 and a lower casing electrical circuit and rotation in the opposite didisc 3, preferably of insulating material, the two 5 rection breaks the contact, the rotation of the being joined by a casing side wall 4. This lat- 5 main operating shaft of the switch being capable ter may of course be of metal, if desired. A main of continuous progression. operating shaft 5 is journaled in end walls 2 Among the objects of my invention are: and 3 in bearings 6 and I so that it may rotate To provide a rotary switch operating only upon freely in either direction. 10 change of direction of rotation; to provide a con- Mounted on the shaft adjacent the bottom tinuously rotatable switch member operating bearing 1 is a collar 8 bearing a friction flange 9.

electrical contacts only upon change in direction Also slipped over the shaft is a contact disc l8,

of rotation; to provide a switch having a wipfree to rotate on the shaft, and one side of this ing contact; and to provide a simple, eflicient disc bears against friction flange 9.

and self-cleaning rotary switch. On the other side of the contact disc 10 I My invention possesses numerous other objects prefer to mount a friction clutch comprising a and features of advantage, some of which, tofriction disc H of insulating material, a spring gether with the foregoing, will be set forth in bearing disc i2 and a spring l3,this latter spring the following description of specific apparatus being slightly bowed, and applying pressure on embodying and utilizing my novel method. It is the clutch discs. The spring is tensioned by lock- 20 therefore to be understood that my method is ing collar i4.

applicable to other apparatus, and that I do not It can be readily seen that the switch can be limit myself, in any way, to the apparatus of assembled quickly by mounting collar 8 on the the present application, as I may adopt various shaft 5, dropping the end of the shaft into bearother apparatus embodiments, utilizing the mething 1, placing on the shaft contact disc Hl, clutch 25 0d, within the scope of the appended claims. discs H and I2, then spring i3 and finally collar Referring to the drawing: M. Top casing disc 2 is then slipped over the Figure 1 is a diagrammatic representation of shaft to clamp side wall 4 between the two casthe switch of my invention as applied for use in ing discs.

controlling a vehicle stop light. Before final assembly, however, I prefer to 30 Figure 2 is a diagrammatic view partly in secmount between casing discs 2 and 3 a pair of tion, showing the switch of my invention utilized upright pins I 6 and I1. These pins carry stain a doorbell circuit. tionary contacts [8 and IS in the form of springs Figure 3 is a longitudinal view through one preextending peripherally on the outside of the conferred form of rotary switch. tact disc ID to terminate on the disc, opposite 35 Figure 4 is a view partly in section and partly each other. I also prefer to provide notches 20 in elevation, taken as indicated by the line 4-4 in the contact disc l0, and position the pins IS in Figure 3. and I! so that they will be within these notches Figure 5 is a similar view, taken as indicated as they pass through the switch chamber. The

40 by the line 55 in Figure 3. edges of these notches will then determine the 40 The great majority of rotary switches now in arc of rotation allowed to the contact disc l0. use are operated through the medium of a main I also prefer to use these pins l6 and I! to clamp shaft rotatable to open or close electrical conthe case together after switch assembly, and tacts. They are so connected to the operating inasmuch as contacts l8 and I9 are attached to mechanism that continuous rotation of. the opthese pins, they may also be used conveniently 45 crating shaft is notpossible in either direction. for exterior connection to the switch, as shown My switch, herein'described and claimed, differs in Figure 3.

from this type of switch in that continuous rota- Mounted on the periphery of the contact disc tion of the main operating shaft is possible, the i0 are a pair of segmental contacts 2|, preferably switch contacts being operated only upon change connected together by conducting link 22 crossing 50 of rotational direction. The switch, thus operthe disc, and in assembling the switch mechaated, has many uses, several of which will be nism I prefer to position notches 20 such that at described later. one end of the disc travel contacts 2| and link Referring directly to the figures for a more 22 will complete the circuit between stationary detailed description of a preferred embodiment contacts l8 and I9, whereas when the rotation of the .disc is reversed and the edges of notches 20 limit the travel'of the disc in the. opposite direction, the segmental contacts 2| are removed from contact with stationary contacts l8 and l9,

thus providing a break.

I have therefore allowed only a short are of rotation to disc it. At one end of this are the circuit is made; at the other end of the arc the circuit is broken.

While I have shown double contacts'in the present example, it is obvious that a single contact disc may also be used, and in this case one of the contacts 2i and contact i9, for example, may be omitted and link 22 connected frictionally to the shaft of the switch so that an'operating connection may be made, for example, to bearings fi or I, but I prefer to use double contacts.

The operation of the switch disc is free to move with the shaft as it is rotated within the limits ofnotches 20, due to the fricjtion in the clutch'assembly. 'As soon as the edges of notches are engaged, however, by pins 15 and I1, rotation of the disc will stop. Rotation of the operating shaft, however, can continue, the friction clutch assembly merely slips. The instant the direction of rotation is reversed the disc will immediately rotate across the arc of notches 20. The circuit is made or broken in accordance with the direction of rotation of shaft 5.

Such a switch has several uses, one of the most important being as a stop light control for automobiles, as shownin Figure 1. Here, an engine 25 is controlled by a throttle rod 26 leading to a throttle control or accelerator 2'I.' Spring 1 28 tends normally to keep the throttle closed, or

nearly so.v H

An operating arm 29 is placed on the operating shaft 5 and connected to the throttle rod through a link mechanism 30 in such a manner that as the throttle rod moves to open the throttle, circuit from battery 3| to stop light 32 is broken. However, the instant pressure on accelerator 21 is removed and the throttle starts to close through the action of spring 28, the direction of rotation of shaft 5 is reversed and contact is made in the switch, thus lighting the stop light and indicating to those behind the vehicle that deceleration may be expected. Immediately upon the throttle being opened again the stop light will go out, due to rotation of shaft 5 in the opposite direction. Inasmuch as shaft 5 may rotate any desired amount without operating the switch, unless direction of rotation is changed, the stop light will operate in any position of the throttle, either full open, fully closed or at any intermediate stage.

At all times the switch will indicate whether I or not the throttle is being opened or closed.

Furthermore, if the throttle is being opened continuously to a certain point, and this point maintained without closing the throttle at any time, the disc ill will stay in position so that the light will not light. Likewise, if the throttle is reduced the stop light goes on, and if the throttle is not againadvanced immediately the stop light will stay on during further reduction or until the throttle is again opened.v

One of the advantages of my switch, as applied to the throttle, is that it does not have to be adjusted to any particular location or to any particular part of the throttle'rod. Inasmuch as the main operating shaft is continuously rotatis simple. The

abIe a'rm 29 may be loosened on the shaft, the switch placed at any desired location, and the operating ,rod 30 may then be clamped onto the throttle rod, as may be convenient. The arm 29 may then be fastened to the shaft, and the button 36 mounted on any convenient foundation 31. In this case I use a special return spring 39 to return the switch to off-position. I have found that such a switch, used asa doorbell, is -exceptionally reliable, and it is well known that doorbell switches in general use 'do not retain their original switching properties for any great length g of time. u

/ Inasmuch as many other uses of the switch of my invention will be obvious to those skilled in the art, I will not-cite many other examples, which will be at once apparent as falling Within the scope of the claims appended hereto.

1 Claim:

1. A rotary switch comprising a shaft to be rotated, a disc free to revolve .on said shaft, a friction clutch connecting said shaft and said disc, a segmental contact on said disc, a stationary contact positioned to bear against said segmental contact upon one rotational position of said disc, and means forlimiting the rotation of said disc to an are including both make and break of said contacts irrespective of the amount of rotation of said shaft, saidmeans including a recess in said disc and a stop member fixed relative to said disc and adapted to'engage in said recess.

/ 2. A rotary switch comprising a casing, a shaft journaled in said casing, a disc within said casing and frictionally rotated by said shaft, a pair of opposite peripheral and electrically connected opposite conductive risers fixed to said casing, spring contacts attached to said risers and hearing against the periphery of said disc, and positioned to be electrically connected at one rotational position by said peripheral contacts, said disc being notched to form a recess for said risers, the edges of the notches forming stops lim-. iting rotation of said disc to an are including make and break of said contacts by engagement with said risers.

' 3. In a vehicle driven by an engine having a movable speed control and a stop light circuit, a rotary switch in said circuit comprising a shaft to be rotated, a disc frictionally mounted on said shaft, a segmental contact on said disc, a sta- 4. In a rotary switch according to claim 1, a

casing for said switch held together by the stop member. f

' CLARENCE B. HOWARD.

' contacts ,on the periphery of said disc, a pair of 

